Microbiocidal use of 1,2-benzisothiazolin-3-ones

ABSTRACT

Certain 2-( omega -substituted alkyl)-1,2-benzisothiazolin-3ones, are useful as fungicides and may be used to protect exterior paint surfaces from mildew attack by incorporation in the paint composition.

gited Stah 1] 3,821,389

Grivas 1451111111; 28, 1974 1 MICROBIOCIDAL USE OF 3,065,123 11/1962 Hinton et al 424/270 12 BENZ]S01H]AZ0L]N 3 0NES 3,517,022 6/ 1970 Miller et a]. 424/270 75 I 1; hC.G' Hll (1,111. I f Jo n f' i FOREIGN PATENTS OR APPLICATIONS [73] Ass'gnee' g' 'g 'gx 848,130 9/1960 Great Britain 424/270 eve 1 861,379 2/I96l ,Great Britain 424/270 [22] Filed: Nov. 15, 1971 1 Appl No: 199007 Primary Examiner-Albert T. Meyers Relat d U,S, A li ti 'p w Assistant Examiner-D. W. Robinson [63] Continuation-impart of Ser. No. 873,071, Oct. 3|,-

I969, abandoned.

1521 11.8.01... ..424/270, 106/15 AF BS RACT [51] Int. Cl. A0ln 9/12, AOln 9/20 [58] Field of Search 424/270; 260/304; Certain Z-(w-subStituted alkyl)-l,2-benzisothiazolin- 106/15 AF 3-ones, are useful as fungicides and may be used to protect exterior paint surfaces from mildew attack by 56] References Cited incorporation in the paint composition.

UNITED STATES PATENTS 3.012.039 l 2/I96l Morley 424/270 21 Claims, N0 Drawings I REFERENCE TO COPENDING APPLICATION This application is a continuation-in-part of US. Pat. application Ser. No. 873,071, filed October 31, 1969, now abandoned.

BACKGROUND OF THE INVENTION Mildew attack has been a continuing problem in numerous environments where the conditions of humidity and temperature are conductive to the growth of various microbial life. Most climates provide sufficient environment for growth of fungi on organic nutrient surfaces, such as plants, fibers, and coatings. One area which has received great attention is the preventing of mildew fungus growth on exterior organic coatings, especially outside building-paints. These paints are applied for protective and decorative purposes over various substrates, usually wood, metal, concrete or ceramics. Painting and repainting of wood structures in houses and other buildings consumes manpower and materials in great amounts. The blemishing and deteriorating effects of various fungi on exterior coatings result in enormous maintenance problems. Because most paintsare applied by brushing or spraying a liquid coating composition onto the surface, the most common method of preventing mildew is to include in the liquid a fungicidally effective amount of chemicals which kill the fungi responsible for the mildew growth.

Numerous attempts have been made to increase the resistance of exterior coatings to mildew fungi. Inorganic compounds such as zinc oxide or leaded zinc oxide are useful for retarding mildew growth, but these components detract from moisture resistance of the film. One approach to the problem has been the controlled chalking of the film by addition of anatase titanium dioxide pigment; however, this caused more rapid erosion of the coating during weathering.

Because moisture is important to mildew growth, the chemical nature of the organic coating film is significant. Many hydrophobic coatings, such as silicones, vinyls, olefins, etc., are not susceptible to mildew growth because of this. Such hydrophobic films are usually cured by heating, and are not adapted to maintenance coatings. Most 'air-drying paints do contain hydrohilic groups, such as carboxyl, hydroxyl, ether or amine. These paints include the more common alkyl solventtype, water-emulsified latex, and drying oil types.

Mildew growth on exterior organic coatings is 'attrib uted to several fungi. Therelative importance ofdifferent species of fungi is climatically dependent; but, Pullularia species usually account for the major number of fungus colonies on painted surfaces in the United States. In warm, moist climates-suchas the Gulf areas around the 30th parallel, Pullularia species account for about 75% to over 90% of mildew growth. North of the 40th parallel this species amounts'to more than half the growth. In the warmer moist areas, Alternaria species, Cladosporium species, and Penicillium species are secondary causes of discoloration. In the northern climates Aspergillus species also is a secondary mildew fungus.

A number of other micro-organisms, such as Rhodotorula (yeast), Monilia, Mucor and Botrytis, are minor causes of mildew. An organic surface that is a nutrient for some fungi may not be a nutrient for others. Generally, a nutrient for other fungi will also support Pullularia growth. Alternaria occurrence is higher in latex paints, whereas Cladosporium does not thrive on a typical latex film. Rhodotorula is associated mostly with drying oil paint vehicles and areas protected from weathering (e.g., under eaves).

The preferred method for controlling mildew growth on exterior coatings is to incorporate antifungal compositions into the liquid coating material before application to the substrate. In order to achieve uniform distribution of the antifungal additives, the mixing should be performed as an industrial operation, rather than adding the fungicide in the field. For this reason chemical compatibility of the fungicide with the liquid material is important. Many fungicides lose their fungicidal activity prior to being applied in a film. This is particularly significant in latex liquid paints, which are usually alkaline. Thus, container storage life is an important criterion for selecting a paint fungicide. While small amounts of biologically active compounds may prevent deterioration of film-forming materials by anaerobic micro-organisms in a sealed can, the most important function of paint fungicides is the prevention of mildew on a nutrient surface exposed to ambient air. The weathering environment to which most exterior coat- .ings are exposed proves tobe detrimental to the biological activity of many chemical compounds.

.Other chemical and physical properties to be considered for fungicide additives include animal toxicity, color, solubility (especially in water), film permeability, volatility and odor. Mercury compounds, such as phenyl mercuric phthalate, are effective against some fungi, but harmful to humans and do not prove dependable under field conditions. Dark materials, such as cuprous oxide, cannot be used in light-colored films. Many sulfur-containing compounds, for instance mercaptans,-give an unpleasant or noxious odor to the coatings. Nitrogenous compounds often interfere with drying properties of oil paints. If a fungicide is too water soluble, it may be leached from the film by condensed moisture or precipitation. If the fungicide does not migrate through the coating film, it may remain buried below the paint surface and be ineffective. The mere fact that a chemical compound is known for its activity against fungi does not'mean that'it will be successful for inhibiting fungal growth on exterior surfaces for long periods of time.

Several organic compounds have gained acceptance as exterior paint fungicides. Captan (N- trichloromethylmercapto-4-cyclohexene-l ,2-, carboximide) has been used for this purpose, and is effectiveagainst Pullularia and other fungi. Trans-1,2-bis (-n-propylsulfonyl) ethylene (U.S.'Pat. No. 3,199,990) is highly effective in alkyd and oil paints. 2,3,5,6- Tetrachloro-4-(methyl-sulfonyl) pyridine is used in many latexpaints as fungicide.

Deterioration and discoloration of exterior films by microbial growth are discussed by Rothwell in the F.P.V.P.C. Oflicial Digest, April, 1958, pp. 368-376. Several fungi, yeast and bacteria species are known to cause mildew growth on exterior paints, but Pullularia has been reported as the major cause in over of reported cases.

BRIEF SUMMARY OF THE INVENTION A high degree of growth inhibition against fungi has been discovered for Z-(w-substituted alkyl)-l ,Z-ben- EXAMPLE 2: 2-(2-iodoethyl)-l .2-BENZIOSOTHIAZOLIN-3-ONE A mixture of 106 parts 2-(2-chloroethyl-1.2-benzisothiazolin-3-one (0.5 mol) was prepared in Example 1.

5 and 89 parts sodium iodide (0.6 mol) is refluxed in acetone with stirring for about 24 hours. The precipitated sodium chloride is filtered off. and the filtrate cooled to yield 96 parts of crude product. Two crystallizations Analysis:

Calculated for C H INOS'. C. 35.43; H. Found: C. 35.51; H.

2.64; N. 4.59: S. 2.55; N. 4.72; S. 1059; l. 41.56

where n is 1 or 2 and Y is selected from the group confrom acetone gives 72 parts the pure compound: m.p.

sisting of halogen, -CN, -SCN,

. EXAMPLE 3; m Z-CYANOMETHYL-l,2-BENZ1SOTH1AZOLIN- is 3-ONE Through a suspension of 220 parts 2,2-

and -CH(OCH Superior antifungal performance is achieved using at least one of these benzisothiazolinones to protect outside house paint under conditions of high humidity and temperature. About 1% of the compound incorporated in a liquid coating composition is sufficient to obtain mildew resistance.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples are givenas representative of the invention, but the inventive concept is not limited to such examples. Units are expressed as parts by weight unless otherwise stated.

dithiodibenzoyl chloride (0.64 mol) in about 1,040 parts of carbon tetrachloride at 25 30" C., dry chlorine is bubbled until practically no solid is left in suspension. The solution of o-chlorothiobenzoyl chloride obtained is then clarified by gravity filtration and added incrementally with cooling to a stirred solution of 10.1 parts freshly prepared aminoacetonitrile (0.18 mol) in about 320 parts of pyridine at ambient temperature. The reaction mixture is stirred at ambient temperature for about 2 hours, filtered, washed with cold water, and refiltered. The carbon tetrachloride layer is then separated and evaporated to dryness under reduced pressure to yield 68 parts of crude product, m.p. 140-l43.- C. Further purification by crystallization from a ben- Analysis:

82; H. 3.1 ;N, 14.72; S. 4; H. 3.2 N, 14.52. S.

EXAMPLE 1: zene/hexane mixture and from benzene gives the pure 2-(2-CHLOROETHYL)-1,Z-BENZISOTHIAZOLIN- compound, m.p. 143-145 C.

3-ONE EXAMPLE 4: Z-PHENACYL-l .2IBENZISOTHIAZOLIN-3-ONE A solution of 89 parts o-chlorothiobenzoyl chloride (0.43 mol) prepared as in Example 3 is added simultaneously with 10 parts sodium hydroxide (0.47 mol) in parts water to a stirred solution of 80 parts aminoacetophenone hydrochloride (0.47 mol) in 1,000 parts water at temperature maintained below about 10 C. The precipitated solid is purified by crystallization A solution of 178 parts (1.5 mols) thionyl chloride in 1,500 parts chloroform is added incrementally with stirring to 284 parts (1.4 mols) 2-(2-hydroxyethyl-l ,2- benzisothiazolin-3-one) kept 65 C.

The solution is then refluxed for 1 /2 hours, and the solvent evaporated to dryness to yield crude product in the form of an oil which solidified upon standing. The crude product is purified by recrystallizations from acetone and, finally, from ethanol to yield pure 2-( 2- chloroethyl)-1,2-benzisothiazolin-3-one, m.p. from benzene to yield 52 parts of product, m.p. 94.5-95.5C. 156-158 C.

Analysis:

Calculated for C.H,C|Nos: c.5059; 11.3.77; Cl.16.59; N.6.56; 5.15.01 Found: c.5055; H.3.86;C1.16.53; N.6.79;S.15.44

Analysis:

Calculated for C,,,H,,NO,S: C. 66.89; H. 4.12; N. 5.20; S. 11.90 Q Found: C. 66.91; H. 4.29; N, 5 14; S. {2.13 a

EXAMPLE 5: Dry chlorine is bubbled through a suspension'of 343 2-(2-CYANOETHYL)-1,2-BENZ1SOT1-llAZOLlN- parts 2,2'-dithiodibenzoyl chloride (1.0 mol) in 1,600 3-ONE parts carbon tetrachloride at room temperature until a A mixture of 107 parts 2-(2-chloroethyl)-l,2 benclear solution is obtained. Excess chlorine is removed zisothiazolin-3-one (0.5 mol), 49 parts sodium cyanide 5 under vacuum at 2530 C. The filtered solution is (1.0 mol), and parts sodium iodide (0.01 mol) in added incrementally to avigorously agitated solution of about 1,600 parts acetone is refluxed for about 16 205 parts aminoacetaldehyde dimethyl acetal (1.95 hours and filtered hot. The filtrate is cooled to precipimol, H N-Cl-l -CH(OCl-l in 980 parts pyridine tate 58 parts of product, which is purified by recrystalliwhile maintaining the reaction temperature at 30 zation from acetone, m.p. 158l 59 C. 10 C. with cooling. The mixture is allowed to stand over- Analysis:

Calculated for c mmosz C. 58.80; H. 3.95. N. 13.72; S. 15.70 Found: C. 58.83; H. 3.96; N. 13.76; S. 15.60

EXAMPLE 6: night and then is poured into about 2,000 parts of ice- 2-(2-HYDROXYETHYL)-1,2-BENZ1SOTHIAZO- water. The carbon tetrachloride phase is separated LlN-3-ONE P-TOLUENESULFONATE ESTER 20 from the aqueous phase, which is washed twice with To a solution of 195 parts 2-(2-hydroxyethyl)-l,2- 4,000 parts carbon tetrachloride. The washings are benzisothiazolin-3-one (1.0 mol) in about 360 parts combined with the organic phase and dried over anhypyridine is added incrementally with stirring at ambient drous calcium sulfate. After evaporation under vacuum temperature 210 parts of solid p-toluenesulfonyl chlor- 269 parts of crude syrup are obtained. The crude is Analysis:

Calculated for C H, -,NO S: C, 55.21; H,

47; N. 5.8 51; N. 6.08; S, 13.65

ide (1.1 mol). The reaction mixture is stirred at 20 C. crystallized from hexane to yield 220 parts of pale yelfor 3 hours, diluted with about 2,600 parts of dilute low crystalline compound, m.p. 53.5-55.5 C.

(about hydrochloric acid, and e pre ipitated The assigned structures are confirmed by infrared solid is filtered off to yield 370 parts of crude product. and nuclear magnetic resonance studies.

This is urified by two recrystallizations from acetone to yield 254 parts of pure product. The analytical sam- MICROBIOLOGICAL ACTIVITIES"SERIAL ple is recrystallized again from acetone, m.p. DILUTION TESTS l47.5-148 C. The intrinsic fungicidal activity of the substituted- Analysis:

Calculated for C"H,,NO4S=: C, 55.00; H. 4.33; N, 4.01; S 18.35 Found: C. 54.84; H. 4.38; N, 3.96; S 18.47

EXAMPLE 7: i I alkyl benzisothiazolinones compounds were investi- 2-(2-TH1OCYANOETHYL)-1,2-BENZ1SOTH1AZO- gated to determine the minimum inhibitory concentra- LIN-3-ONE tion in vitro against Pullularia pullulans (P.p.) and Penicillium oxalium (P.o.). The samples were dissolved in A 'f l' of 166 Parts y y l' 3 a small quantity of organic solvent and made to volume zisothiazol1n-3-one p-toluenesulfonate ester (0.47 mol) i sterile Sab9uraud i i Medium The Samples as prepared in Example 6 and 52 parts potassium thiowere made to various concentrations in the nutrient cyanate (0.53 mol) in about 400 parts ethanol is remedium by the serial dilution technique. These were fluxed for 6 hours and evaporated in vacuo to dryness. 55 inocculated with P.p. or P.o. fungi species and incu- The solid is washed 3 times in 1,000 parts water, filbated for seven days at 25 C. The results showed a tered off and dried to yield 98 parts crude product. The minimum concentration against Pullulariz species to be compound is purified by crystallization from acetonelfrom about 1 to 500 parts per million for the various hexane mixture, m.p. 102l03 C. compounds tested. These inhibitory amounts compare Analysis:

Calculated for C,H,.N,OS,: C. 50.82; H, 3.41; N. 11.86. S. 27.14 Found: C. 50.62; H. 3.37; N. 11.74; 5. 26.93

EXAMPLE 8: favorably with commercially available paint fungicides. 2-(2,2-D1METHOXYETHYL)- 1 ,Z-BENZISO- In Table l the results of the serial dilution tests are set THlAZOLlN-Il-ONE forth for the compounds described in Examples 1 to 8.

2-Benzyll ,2-benzisothiazolin-3-one 2-Cyclohexyll ,2-benzisothiazolin-3-one 2-Allyl-l ,Z-benzisothiazolin-3-one TABLE I 2-Methyl-l,2-benzisothiazolin-3-one The alkyd paint contained the following components: Serial Dilution Minimum Example Substituent lnhibitory Concentration soya oil-modified ester of glycerol and No. Radical P p, P o phthalic anhydride 340 parts; linseed oil 73 parts; 1 Lchloroeh 2 2 chlorinated paraffin resin (Chlorowax) 91 parts; 2 zqodoethfl 1 titanium dioxide pigment 200 parts; 3 cyanomethyl 64 alkaline earth silicate l parts; 4 phcnacyl I23 bentonite gel 82 parts; 5 cyanoethyl 500 metal naphthenate dryers 9 parts; 8L 6 hydroxyethyl 500 10 mineral spirits 130 parts.

toluencsulfonatc ester 7 thiocyanocthyl l6 capstan lldlmehmyclhyl l The liquid alkyd paint contained about 87 weight control Solids- A negative control containing no benzisothiazolinone and each of the other paints was then applied to wood chips in the same manner, weathered for the same pe- AGAR PLATE TESTS riod of time and subjected to mildew attack in a modi- A standard laboratory test used to evaluate fungicidal fied tropical chamber. Examination of the samples for properties of compounds is the agar plate test, perfungi growth after 21 days of incubation showed that formed according to USDA. Circular No. 198 (193 l each paint containing benzisothiazolinone (except A Difco potato dextrose agar plate was selected as CEB) had about the same rating as the negative conthe organic nutrient surface. The 2-chloroethyl deriva-, trol, whereas paint containing 2-(2-chloroethyl)-l,2- tive (Example 1) was dissolved in an organic solvent as benzisothiazolin-3-one had a significantly less growth solute in concentrations of l% to 0.01% by weight, and 25 of fungi on the sample. the solution was applied uniformly over the surface of The above accelerated test procedure was followed sterile filter pads inch diameter). After evaporation at a concentration of 1% by weight, comparing the of the carrier liquid, the pads were placed on the agar CEB compound with trans-l,2-bis(n-propylsulfonyl) plates. Both pads and plates were inoculated with a ethylene (Vancide PA), a well-known commercial spore suspension of the test fungi, Pullularia pullulans 3O paint fungicide. Using the alkyd paint formulation (P.p.), Cladosporium sphaerospermum (C.s.), and above, and weathering pine and redwood wood chips Aspergillus niger (A.n.). The compound was also comfor 100 hours with a 21-day incubation period, it was pared to a commercially used fungicide, captan. After found that the CEB compound was equal to the coma period of standard incubation, the pads and agar mercial fungicide in antifungal protection. plates were examined to determine growth of fun- 3 5 The fungicidal w-substituted-alkyl benzisothiazoligus on the pad and to measure the zone width (millimenone compounds may be used with a wide variety of ters) of growth inhibition in the agar plates beyond the oils, resins, solvents, pigments and coating additives in periphery of the smaller treated pad. The results are formulating organic film-forming compositions having shown in Table II. mildew resistance. The more common types of exterior TABLE ll Agar Plate Test Cone P.u. C.s. A.n. (Wt. Zone Growth Zone Growth Zone Growth Compound (mm) (on pad) (mm) (on (on pad) pad) i 2-(2-Chloroethyl) 1 14 0 20 0 13 o 1 .2-benzisothia- 0.1 11 0 12 0 9 0 zolin-3-one (CEB) 0.01 3 0 5 0 1 0 Captan 0.] ll 0 l4 0 l0 0 0.01 5 0 9 0 4 0 Control 0 O 0 0 ACCELERATED PAINT TEST coatings for which these compounds are useful as fungicides include the drying oils, alkyds and latex-type A Severe test to eYaluate f gf F for P m 15 F l paints. The film-forming vehicles include the triglyceraccelerated Weathering test, Whlch helpful antlclide esters of unsaturated fatty acids, such as linseed oil patmg field performance (PA. Wt)" at a Ameror soya oil; esters of polycarboxylic acids with polyols, Chem- SOC- Dl O COa g and Pl8SllCS,'25, 23 such as reaction products of phthalic anhydride with This methodwas used to test and compare several glycerol or pentaerythritol; oil-modified alkyds; modibenzisothiazolinones as follows: fled phenolic resins, such as aldehyde condensation;

A 1% concentration of each of five benzisothiazolimelamine resins; synthetic elastomeric latexes; homonones in alkyd paint was prepared in the same manner. polymers or copolymers of olefinically unsaturated The five compounds were: compounds, including vinyl acetates and acrylic resins;

2-(Chloroethyl)-l ,2-benzisothiazolin-3-one (CEB) urethane resins; ether resins and numerous other conventional coating vehicles. Typical pigments which can be combined with the film-forming organic binder in exterior paints comprise titanium dioxide, alkaline 9 earth carbonates and silicates, bentonite, mica, metal oxides, carbon, etc. Solvents and co-solvents are used conventionally in both organic-thinned or water thinned coating compositions, for instance, mineral spirits, polyols, benzenoids, etc. Numerous additives can be incorporated in the antifungal paints for suppressing foam, for plasticizing the dried films, for emulsifying latexes, or for accelerating the film cure.

While the antifungal additive is usually incorporated directly into a coating to be-applied as a-top coat, some organic coatings can'be adequately protected by using the antifungal additive in a primer or intermediate coat. Migration into an adjacent layer from a substrate containing a fungicide can be an effective means for controlling mildew in some applications. A relatively higher local concentration of fungicidal agent may be necessary under-such conditions. Direct application of the fungicide with an inert carrier'over the organic nutrient surface may be used to protect against fungus growth, but this method may not be desirable for exterior weathered surfaces due to erosion. Some interior surfaces in food processing rooms, such as bakeries, breweries, meat packing plants, etc., also suffer from mildew growth clue to extreme conditions of humidity or temperature. Here the weathering effect is not such an important factor, but the use of a fungicide is desirable.

The preferred concentrations of benzisothiazolinones in the dry coating films is from the minimum inhibitory amount to about 2% by weight. Greater amounts may be used, but no particular benefit is gained from using concentrations much higher than the minimum fungicidally effective amount of at least one of these compounds.

While the invention has been described by specific examples, there is no intent to limit the inventive concept except as set forth in the following claims.

I claim:

l. Aprocess for controlling growth of fungi which comprises gontacti r g il i e jgigLwilhuafungicidally effective amount of at least one compound having the structure:

where n is l or 2 and where Y is selected from the group consisting of Cl, I,

and CH(OCHa)2- 2. The process of claim'l wherein n is l and Y is -CN.

3. The process of claim lwherein n is 2 and Y is -CN.

4. The process of claim 1 wherein n is 2 and Y is Cl.

5. The process of claim 1 wherein n is l and Y is 6. The process of claim 1 wherein n is 2 and Y is 7. The process of claim 1 wherein n is 2 and Y is -SCN.

8. The process of claim 1 wherein n is l and Y is -CH(OCH 9. Theprocess of claim I wherein n is 2 and Y is l.

10. A mildew resistantorganic coating composition containing a film-forming organic binder and a fungicidally effective amount of at least-one compound having the structure:

where n is l or 2 and where Y is selected from halogen,

:CN.-$ N!.

and 7 11. A process for controlling growth of fungi which comprises contacting the fungi with a fungicidally effective amount of a compound having the structure:

fective amount of a chemical material having the structure: 1

.where n is l or 2 and where Y is selected from the group consisting of Cl, 1, -CN, -'SCN-,

and -CH(OCH 13. The process of claim 12 wherein n is 1 and Y is I 4 The process of claim 12 wherein n is 2 and Y is PS The process of claim 12 wherein n is 2 and Y is l 6. The process of claim 12 wherein n is l and Y is 17. The process of claim 12 wherein n is 2 and Y is i 18. The process of claim 12 wherein n is 2 and Y is -SCN.

19. The process of claim 12 wherein n is l and Y is -CH(OCH wherein n is 1 or 2, and wherein Y is halogen, -CN,

-SCN,

0 CO saga,

or -CH(OCH said benziosothiazoline being present in a concentration up to 2% by weight of the coating, -dry basis. 

2. The process of claim 1 wherein n is 1 and Y is -CN.
 3. The process of claim 1 wherein n is 2 and Y is -CN.
 4. The process of claim 1 wherein n is 2 and Y is C1.
 5. The process of claim 1 wherein n is 1 and Y is
 6. The process of claim 1 wherein n is 2 and Y is
 7. The process of claim 1 wherein n is 2 and Y is -SCN.
 8. The process of claim 1 wherein n is 1 and Y is -CH(OCH3)2.
 9. The process of claim 1 wherein n is 2 and Y is I.
 10. A mildew resistant organic coating composition containing a film-forming organic binder and a fungicidally effective amount of at least one compound having the structure:
 11. A process for controlling growth of fungi which comprises contacting the fungi with a fungicidally effective amount of a compound having the structure:
 12. A process for controlling growth of fungi which comprises contacting the fungi with a fungicidally effective amount of a chemical material having the structure:
 13. The process of claim 12 wherein n is 1 and Y is -CN.
 14. The process of claim 12 wherein n is 2 and Y is -CN.
 15. The process of claim 12 wherein n is 2 and Y is C1.
 16. The process of claim 12 wherein n is 1 and Y is
 17. The process of claim 12 wherein n is 2 and Y is
 18. The process of claim 12 wherein n is 2 and Y is -SCN.
 19. The process of claim 12 wherein n is 1 and Y is -CH(OCH3)2.
 20. The process of claim 12 wherein n is 2 and Y is I.
 21. A process for controlling growth of fungi on an organic coating containing a film-forming organic binder which comprises contacting the fungi with a fungicidally effective amount of omega -substituted alkyl 1,2 -benzisothiazolin-3-one having the structural formula; 